In broadest terms, the objectives of this Psychopharmacology Research Center Grant are the elucidation of the mechanism of action of psychotropic drugs in animals and man and the transformation of the Clinical Division of the T.N.I. into a unit for clinical research in Biological Psychiatry where hypotheses generated by basic scientists and clinical psychiatrists can be tested. To achieve these goals, the following aspects of the pharmacology of psychotropic drugs are emphasized: 1. Metabolism of psychotropic drugs in animals and man. 2. Studies of neurochemical, neurophysiological and behavioral correlates of psychotropic drug action. 3. Elucidation of regulatory and adaptive mechanisms at pre-and postsynaptic sites of aminergic systems and their modification by acute and chronic administration of psychotropic drugs. 4. Inter-relationships between various neuronal transmitter systems (adrenergic, serotonergic and cholinergic) and its modification by acute and chronic administration of psychotropic drugs. 5. The identification of psychoactive characteristics and the determination of the therapeutic efficacy of new drugs in patients with various mental disorders.